Australian miner Bathurst Resources' ability to deliver a significant area of environmental protection on the Denniston Plateau is critical to its success before the Environment Court.

Both environmentalists and Bathurst say that is the main issue to be nailed down, following the interim consent for the Escarpment opencast coalmine announced by the court on Thursday.

However, they disagree about how difficult it will be for the NZX-listed coalminer.

Bathurst Resources has a tentative green light for its Escarpment Mine Project which would dig up about 5.8 million tonnes of high-grade coking coal from a 157-hectare block on the Denniston Plateau on the West Coast.

In the interim judgment, Environment Court Judge Laurie Newhook and environment commissioners Carron Blom and Russell Howie said the case was finely balanced.

Ultimately they were inclined to grant consent - but only if the conditions were adequate.

"Put plainly, we consider that the draft as presently offered by [Bathurst Resources] contain too many ‘best endeavours' type conditions, with limited certainty of outcome," the interim decision said.

The plateau was part of an endangered ecosystem and its degradation had to be weighed.

The court's concerns could be allayed if a protection area could be created - the proposed area would cover 40 per cent of the plateau - but "best endeavours" were not strong enough to be relied on, they said.

The proposed protection area is 745ha that would be protected from mining and other disturbance forever, despite it not having coal beneath it. For that to happen, the landowner - the Department of Conservation - would need to give its permission along with the Ministry of Business, Innovation and Employment and the ministry's NZ Petroleum and Minerals division. Fairfax NZ